1. Field of the Invention:
The present invention relates to a rotor which has a plurality of permanent magnets on the peripheral surface of a rotary shaft.
2. Description of the Prior Art:
A rotor having permanent magnets has been proposed in Japanese Patent Laid Open-Application No. 58-123355, wherein a rotary shaft is provided which has an orthogonal cross-sectional shape in a longitudinal direction thereof, and a plurality of circular-arc portions which center around an axis of rotation of the rotor shaft, as well as rectilinear portions which respectively connect adjacent circular arc portions with straight lines having no curved portion. A plurality of permanent magnets, equal in number to the circular-arc portions are respectively fixed in opposition only to the rectlinear portions.
In, for example, Japanese Utility Model Registration Application Laid-Open No. 55-120283, a rotor of the aforementioned construction is proposed which is easier to manufacture and which prevents the permanent magnets from turning relative to the axis of rotation against torques which act on the magnets.